The number of Bitcoin core developers reaches a recent high, with technical and market signals jointly pointing to a new cycle in 2026.

Entering 2026, the Bitcoin network is signaling a long-term trend that is often overlooked by the market—sustained growth in core developer activity. Jameson Lopp, Chief Security Officer of Casa and an early Bitcoin participant, recently disclosed on X that in 2025, a total of 135 developers contributed to the Bitcoin core codebase, significantly higher than the 100 in 2024. This change is seen as an important sign that Bitcoin is transitioning from a “maintenance phase” back into an “innovation cycle.”

The increase in the number of developers is not an isolated phenomenon. Data shows that the subscription count for Bitcoin development mailing lists has increased by approximately 60% year-over-year. Although discussion volume on mailing lists declined at times over the past two years, recent activity has clearly rebounded, indicating renewed discussions around protocol upgrades, consensus mechanisms, and long-term evolution. For a decentralized network known for stability, this resurgence in discussion density often signals that new technological directions are brewing.

On the code level, the total number of Bitcoin core code modifications in 2025 reached 285,000 lines, with 2,541 commits throughout the year—about a 1% increase year-over-year. While the growth rate is modest, in the context of Bitcoin’s emphasis on security and conservative evolution, this steady increase itself sends a positive signal. More importantly, the developer structure has become more diverse, helping to reduce single-point risks and enhance the network’s long-term resilience.

Support from the financial side is also progressing in tandem. Global asset management firm VanEck has stated that if its Bitcoin ETF-related proposals are approved, it will allocate 5% of ETF earnings to continuously support Bitcoin core development over the next decade. This long-term, institutionalized financial commitment provides a more stable foundation for the open-source developer ecosystem.

In terms of security, Bitcoin also made key progress in 2025. Cybersecurity firm Quarkslab completed its first public third-party audit of the Bitcoin core codebase. The audit lasted four months, funded by Brink and coordinated by OSTIF. No medium- or high-risk vulnerabilities were found; only two low-risk issues and several optimization suggestions were identified, further reinforcing Bitcoin’s market reputation as the “most secure blockchain.”

From a market perspective, improvements in the technical fundamentals are resonating with price structure. In early January, Bitcoin completed a structural strengthening on the 4-hour chart, with the Ichimoku Cloud indicating continued upward momentum. The current demand zone is between $91,600 and $92,100, while around $90,500 remains a key support level. As long as the price stays above the cloud, Bitcoin’s medium- to short-term trend remains bullish.

Overall, the growth in developer numbers, increased code activity, robust audit results, and technical strength collectively form a deep bullish case for Bitcoin in 2026. For investors focused on Bitcoin’s long-term value, fundamental analysis, and core development dynamics, this shift may be as significant as any price breakout.